1. Field of the Invention
The present invention relates to an interchangeable lens including a diaphragm operation member, and a camera lens system including the interchangeable lens.
2. Description of the Related Art
Conventionally, as a diaphragm control system of a lens attached to a lens interchangeable camera, for example, there is a system in which a camera side transmits a desired diaphragm driving amount to the lens by a communication unit, and the lens drives a diaphragm by the received driving amount to control a light amount. To improve operability during moving image capturing, there is a system which includes an electronically-controllable diaphragm operation member on a lens side, and enables the lens side to instruct a diaphragm driving amount.
Japanese Patent Application Laid-Open No. 06-186626 discusses a configuration in which a diaphragm operation member of a lens side can control a diaphragm when a diaphragm operation switch of the lens side is in an operation permitted state.
Japanese Patent Application Laid-Open No. 2009-53599 discusses a system in which a camera determines whether a lens includes a diaphragm operation member and, when the lens includes the diaphragm operation member, allows selection as to which of diaphragm operation members of a camera side and a lens side is preferentially used.
However, in the technique discussed above, a case where the camera includes no unit to determine whether the lens side has a diaphragm operation member is not referred to. In the technique discussed in Japanese Patent Application Laid-Open No. 2009-53599, the camera uses exclusive communication function to determine whether the lens side includes a diaphragm operation member.
However, depending on a difference in release time of cameras, the camera may not include such exclusive communication function. When a lens equipped with a diaphragm operation member is loaded on the camera having no exclusive communication function, the camera side cannot determine whether the lens includes the diaphragm operation member.
In this case, when the diaphragm operation member of the lens side is operated while an operation of the diaphragm operation member is permitted, the camera side receives information on a diaphragm operation from the lens side irrespective of no command issued to operate a diaphragm. The camera side may then determine that the lens side is performing an operation different from that by a command of the camera side, and stop the system.